Friction material



Patented May 6, 1930 iiNITED STATES PATENT FFICE ALFRED L. BOEGEHOLD AND CHARLES R. SHORT, OF DETROIT, MICHIGAN, ASSIGNORS T GENERAL MOTORS RESEARCH CORPORATION, OF DETROIT, MICHIGAN, A COR- ronnrroir or; iinralmraien FRIGTION MATERIAL' Application rled February 23, 1927. Serial No. 170,336.

This invention relates to brakes and clutches used on automotive vehicles and particularly to the linin therefor.

In the ast it has pose the rake and clutch lining of a base of fibrous material and im regnate this iibrous material with a suitab e filler, the compound used for the filler usually being a hydrocarbon. In the present invention it is proposed to use the same fabric oriibrous base but to impregnate'it with a metal stead of the hydrocarbon compounds heretofore used.

ln the present invention the fibrous ina-- terial or fabric composed of individual strands and constituting the base is prefer-u ably of asbestos and may have a flux composed of a metallic salt applied thereto and afterward immersed in a bath of molten metal. This will give a filler of metal through the interstices of the fibrous base. 'I hedmalterial may later be compressed if desire instead of the method above described we may coat the individual strands of the brous material with metal before they are woven into the fabric. After the Weaving operation the material may be' sintered to cause the adjacent strands to adhere together, after which a rolling or pressing operation may be advisable.

A; third method of forming our improved bralre` lining is to coat the threads (which constitute the fabric base) with a sheathing of metal by electrolysis. After the threads are -the individual strands before weaving to the fabric, with a powdered metal and after the weaving operation, to sinter the material. A compressing operation may later' be performed.v p

A still further method of producing the finished article is to `apply a suitable flux on both sides of the woven fabric and placing a thin layer of metal` over the ux and by the en customary to comterial is still at a high temperature.

An inorganic material such as graphite, or a hydrocarbon compound, may be entrained in the material' either before or after the sintering, operation, or immediately before the final pressing or rolling.

One form or embodiment of the invention is disclosed in the ligure `on the accompanying drawing. p Referring to the numbered parts of the drawing, 1 designates the fabric or fibrous base of the lining material, 2 the flux and 3 the outer coatings of metal, preferably iron. The hun and metal may be applied to but one side, or to both sides as shown in the drawing, but we prefer to apply it to both sides in order to obtain a more intimate intermingly of the molten metal in the interstices of the brous material.

When the component parts are assembled in the relation shown in the drawing, heat is applied and the metal 3 caused to iiow and run into the interstices of the fibrous base l.

lhe material may later be rolled or pressed, either while it is in vits heated state, or afterward when it has cooled. The material is then ready for use as a :brake hrung, or

on clutches. thus coated they may be woven into the band Our improved brake lining, is not subject to chan ing characteristics,such a common and obgectionable feature of the existing brake linings. This change in characteristics is due to temperature rise during operation or application of the brake or clutch. l

Metallic friction members are noisy and in the present invention it is proposed to make use of the frictional' properties of metal, but reduce the noise so that it is no longer objectionable. rlhis we accomplish by causing molten metal to flow into a fibrous or fabric base, preferably of asbestos, and using the ,nished article as a brake or clutch lining.

We claim.: v

1. The method of makingba, brake lining consisting'of using a brous ase, applying a metal to said baise,A heating the metal so as to cause it to {iow into the interstices of the.

base, and then pressing or rolling the product.

2. The method of making a brake lining onsistin of applying a fiux to a, brous base, then app Iying a metal over the flux, then in heating the whole so as to cause the molten metal to ow into the fibrous base.

n testimony whereof we aix our signatures.

ALFRED L. BOEGEHOLD. CHARLES R. SHQRT. 

